1. Field of the Invention
The present invention relates to a processing apparatus and, more particularly, to a processing apparatus which can be used in a digital signal processing apparatus such as a modem.
2. Description of the Related Art
A real discrete Fourier transform (RDFT) is known. The RDFT algorithm allows a transformation from the time axis to the frequency axis as long as all input data to be handled are real numbers.
It is generally known that a real inverse discrete Fourier transform (RIDFT) algorithm, which is the inverse transformation of the RDFT, can be obtained by executing the above RDFT algorithm in reverse order.
Conventionally, arithmetic processing apparatuses of this type include no arithmetic processing apparatus based on these RDFT and RIDFT algorithms.